Page 39 - Centrifugal Pumps 2E
P. 39
Specific Speed and Modeling Laws 25
Table 2-7
Tabulated Performance at 3,550 RPM
GPM H(ft) Eff. %
0 350 0
100 349 28
200 345 48
300 337 52
400 325 70
500 300 74
600 260 73
650 235 72
Table 2-8
Tabulated Performance at 5,000 RPM
GPM H(ft) Eff. % bhp
0 700 0 91
150 698 28 94.4
300 690 48 109
450 674 52 142
600 650 70 140
750 600 74 153
900 520 73 161
975 470 72 160
For complete performance conversion, see Tables 2-7 and 2-8. The hy-
draulic performance of the new 4-in. x 6-in. x 9-in. pump operating at
5,000 RPM is shown in Figure 2-8.
Conclusion
There is no question that specific speed is the prime parameter for
evaluating design of centrifugal pumps, evaluating pump selections, and
predicting possible field problems. It is obvious, however, that no single
parameter can relate to all aspects of final pump design. Different pump
specifications covering a wide variety of applications force the designer
to consider additional factors that may have an unfavorable effect on
pump hydraulic performance. Predicted performance can be affected by
any of the following:
